The Cannon Beach house, built by Nathan Good, architect, and Rich Elstrom Construction. I saw this house first in Fine Homebuilding special edition on green housing. Fine Homebuilding, and the Taunton site in general, has a huge amount of information on green building.

This is the first post in a series on zero-net energy homes. Over the course of the series I will be covering all aspects of this topic, from the technology and knowledge available today, to the changes needed in technology, building codes, trade skills, design approaches, and will to achieve the goal of all new homes eventually being zero net energy.

Definitions and feasibility

What is a “zero-net energy home?” Zero net energy homes generate as much energy as they use. Energy used = Energy Generated. The experience of thousands of “off the grid” home owners and those bleeding edge homeowners with big solar panel installations on their roofs show that zero-net energy homes are technically feasible today. For example, see this article on Amory Lovins’ home and office in Snowmass, CO.

We know how to build them. Unfortunately, for most homeowners, they are too expensive, because the energy generation side of the equation is too costly. There are three ways to address this problem.

Reduce the cost of home-based energy generation, typically either solar or wind. That depends on technological improvements and manufacturing efficiencies by the solar panel companies, and they are busily doing their best to address this situation.

Change the cost basis for comparison – energy generation is expensive compared to the cost of electricity from coal-fired plants, but a carbon tax on those plants would automatically make solar more competitive (and raise the cost of energy for all of us).

Make the demand side of the equation – energy used – smaller. Reducing the energy used by half cuts the energy required by half, which cuts the cost by half. And typically reducing energy use has numerous other cost benefits, and often performance benefits as well.

Over the course of this series of articles, I’ll be looking at how both sides of the equation can be reduced, but the particular focus will be on getting the demand side down.

Privation is not the solution

One way to reduce the energy use of the home is simply to do less – for example, you can save a lot of hot water if you simply stop showering every other day. Other techniques are leave the heater off when it’s cold, or the AC off when it’s hot. There’s also sitting in the dark – lighting accounts for about 15% of home energy use. Strangely, most homeowners in the U.S. are unwilling to reduce their energy demand by cutting “services” in this way.

Therefore, we have to find ways to reduce energy usage while not cutting the “services” the home provides. We all need our showers, our lights, and our comfortable temperatures. The good news is that by making small changes in how homes are designed and built, typically at a very small increment to the cost of the home overall, we can build houses that use one half the energy or less, and often at a higher level of comfort and “service” than standard-built homes.

As we will see over the next few articles, we already have all the technology, and some people have the experience, to build “zero-net energy ready” houses cost effectively.

On the energy generation side, although there’s currently a premium to get to zero-net energy, over the next ten years this premium will go to zero. In fact, looking farther ahead, it may become cost-effective to get to positive-net energy – where the house is generating more energy than it needs! Such a change has world-changing implications – but we’ll cover that later in the series.

Coming up

Zero-net energy homes is a huge topic, and some of the areas we’ll be covering in future posts are:

Integrative design

Passive heating

Home energy storage

Zero-net energy for existing homes

Zero-net energy and LEED

Practical steps for finding a zero-net energy home builder

Examples of zero-net energy homes

Achieving a zero-net energy home cost-effectively

How the cost-benefit equation on zero-net energy homes is likely to change over the next five and ten years

As I get started on this series, I’d love to hear your comments and thoughts on what I’ve presented here, as well as other topics I should cover in future posts.

Snow on the San Gabriel Mountains (photo by Jerry Thompson1, CC 2.0 license)

On December 30 of last year (six days ago), my wife and I were in Pasadena, CA visiting the Greene and Greene exhibit at the Huntington Library. It was one of those glorious and rare smog-free days in the LA basin. The air sparkled, you could see for miles in every direction, and mountain range after mountain range was visible – all the way out to the snow-covered San Gabriels. Nowadays, the air is only ever this clear around the Christmas holiday, when the freeway traffic is substantially reduced and a lot of factories shut down for the week. It got me thinking about how the future – say ten to twenty years hence – may be unrecognizable in both dramatic and mundane ways. For example, smog-free days may no longer be rare in LA, once the economy has shifted off fossil fuels. (I suspect the traffic will remain, unfortunately!)

Like LA’s typical skies, the energy future is murky in the short term – this year and 2010 – and I’ll leave those predictions to others. But the big trends – sustainability, carbon fighting, and technological breakthroughs – enable us to make better sense of the mid- and long-term. Therefore, In the spirit of the New Year, the incoming administration, and the tipping point that the world has come to about climate change and sustainability, here are ten things I believe are very likely to happen in the next ten years.

Residential solar PV will be cost effective in most U.S. locations (via a combination of price reduction, new design thinking, much more efficient homes, and a carbon tax on fossil fuels).

Home energy storage – via batteries, hydrogen reforming, fuel cells, or other technology – will be available and installed in 10% of new homes in California, for when the sun don’t shine.

More than 10% of new homes in California will be zero-net energy.

50% of new residential construction in California will be zero-net energy “ready.”

The current LEED standards will be considered obsolete.

More than 20% of peak grid electricity will come from excess capacity from residential solar PV.

There will be general consensus that efficiency and frugality alone will not provide enough CO2 mitigation to prevent major climate change – we will need a technological solution to actually reducing atmospheric CO2 or artificially cooling the earth.

There will be a mid-priced carbon fiber, plugin hybrid passenger car in production that gets more than 75 miles per gallon. The company making it will be the “next GM.”

10% of the cars on the road will be powered by 100% renewable energy and will be essentially non-polluting.

New technologies for capturing carbon from the atmosphere will be available, powered by excess solar capacity.

What do you think? Am I off base here? Too optimistic? Too pessimistic? Let me know in the comments. I’d love to hear your thoughts, challenges, and predictions for 2018.

Zero-net Energy Series Coming Up

Over the next few weeks, I will be publishing a series on “zero-net energy” residences (related to predictions 1-6 above). This area is about to explode. We already have all the technology, and some people have the experience, to build “zero-net energy ready” houses cost effectively. And although there’s currently a premium to get to zero-net energy, over the next ten years this premium will go to zero, and probably it will be cost-effective to get to positive-net energy – where the house is generating more energy than it needs! Talk about a world-changing situation – it really is possible to have energy too cheap to meter, but it’s going to come off our roofs, not from a nuclear plant or one of those imaginary fusion reactors.

In the last week or two I came across a number of interesting energy-related resources, blogs, websites, and talks that I wanted to share.

I was happy to run across Barry Katz’s new blog, The Future Is Green, because Barry, a home builder, is where all home builders need to get in the next 5-10 years. He’s committed to building zero-net energy homes and remodels. His web site has examples of the some of the work he’s done so far.

In fact, the homebuilding industry can do something that not even hybrid cars can do. It is entirely possible, using currently available technology and materials, to build homes that consume zero-net energy. And not only zero net energy, but energy positive enough to recharge our plug-in hybrids. Such houses exist already. If we can build one, we can build many. (From Barry’s post, What We Need Now.)

Barry’s also writing a book on green remodels, which should be useful for people like me who live in a house that’s already been built.

Saul Griffith, of Makani Power, calculated his current carbon footprint, and then his “allocated” carbon footprint as a global citizen. In this talk at the O’Reilly Emerging Technology Conference earlier this year, he walks through those numbers – which are both scary and heartening. His calculations suggest that we need to throttle our energy usage at about 15 terawatts (TW) for the entire earth. As he puts it:

My life today is 18 horsepower, my new life should be three horsepower

I found the section on the energy available for us to use – the total solar flux, the tidal power of gravity, nuclear, and geothermal – extremely interesting (about 30:30 into the recording).

There are only four sources of energy – sun (85,000 TW), gravity (tidal – 3.7 TW), geothermal (constant flux of 32 TW), nuclear. All photosynthesis is 90 TW, which is the major argument against biofuels.

“He understands that space stretches, he understands that you can stretch time, compress space and therefore he can, in a sense, actually have six Santa months to deliver the presents,” Silverberg told Reuters.

I hope you enjoy these links – let me know your thoughts, especially about the Griffiths talk if you have a chance to listen to it on your iPod – or on your computer at work.

The Rocky Mountain Institute’s Andrew Demaria blogged a few weeks ago about “smart garages” that combine smart cars, a smart home network, and much smarter utilities into a synergistic system that optimizes power usage. After describing a “day in the life” of a smart garage:

Given the utility is experiencing a peak load period, it asks my house if it can use the spare power in the car’s battery and send that electricity elsewhere in the grid. What’s more, it will pay me for that power. Since I like being paid, I have already programmed the system to accept such requests.

The article then goes on to list the highlights of a recent Smart Garages conference organized by RMI. Attendees included representatives from auto manufacturers GM, Ford, and Nissan, utilities PG&E and Duke Energy, and consumer-focused companies Walmart and P&G.

Integrative design like smart garages requires all these organizations to work effectively together, based on official or de-facto standards. Although the cost of making such a transition will be hundreds of billions of dollars, the associated business opportunities, especially for those companies who can help tie all these disparate parts together, are commensurately huge.

From MIT’s Technology Review comes this column from Kevin Bullis, about a recent report from Deutsche Bank on the economic benefits of investing in new energy projects:

It argues that it’s possible to address challenges related to climate change, energy security, and the financial crisis at the same time by investing in four specific areas: energy-efficient buildings, electric power grids, renewable power, and public transportation. The report cites figures that suggest investing in these areas creates more jobs than investing in conventional energy sources because much of the old energy infrastructure is already in place. It says that “a $100 billion investment in energy and efficiency would result in 2 million new jobs, whereas a similar investment in old energy [such as coal or natural gas] would only create around 540,000 jobs.”

Of course, Obama has already pledged to do something along these lines, and the blogosphere (including me, here) has chimed in as well. But the imprimatur of Deutsche Bank adds some gravitas to the proposal.

(Sorry for the dearth of posts recently – family events, as well as me having a cold have impacted my ability to put two words together effectively.)

On Monday I got to see my hero Amory Lovins of the Rocky Mountain Institute address a large crowd at the inaugural address in a new series of Green Speakers in Portola Valley, CA. The talks are in honor of their new, very sustainable Portola Valley Community Center. (They are hoping to be the first LEED Platinum-certified community center in the country.)

Lovins’ talk covered much of the same ground as his Stanford address in September 2007 on Energy Efficiency In Buildings (part 1, part 2). In particular, he presented as examples his home in the Rockies, the Davis energy efficient homes built in the late 80’s and some buildings in Thailand, built in the 90’s. These are great examples, but he’s used them quite a bit, and seems not to have updated his examples recently.

One of my tasks – to get back to my core purpose in this blog of illustrating “profitable applications of green energy (including efficiency) using integrative design” – for the next few months is to find up-to-date examples of the application of Lovin’s and RMI’s ideas and theories and list them here.

Solar power systems covering the areas defined by the dark disks could provide more than the world total primary energy demand in 2006 (assuming a conversion efficiency of 8%). Image from Wikipedia.

I recently asked physicist Richard Muller whether he thought the price-performance of solar electricity generation would follow a Moore’s Law-type curve. He said that this would not occur due to improving the efficiency of solar collection, as the current levels of efficiency – 20-40% – are reasonably high. However, he added

“I do expect the price to drop by a factor of 10, so we will have lots of solar.”

Well, in the nature of things, there’s definitely a limit to how much energy a solar PV collector can get from a square meter of sunlight. (There’s about 1kw of energy in a square meter – as I learned in Physics For Future Presidents, by Professor Muller – so we can expect to get 400 watts or less.) The amount of this energy per square meter we can collect will go up, but asymptotically approach (at best) the physical limits.

On the other hand, I’d argue that the cost of collecting it can go down a nearly unlimited amount – certainly multiple orders of magnitude. So what will solar PV look like in 2018 – ten years from now?

This is a great example that aligns perfectly with the topic of this blog, “Keeping the lights on.”

In its most recent “Environmental Lovins” blog post, Monica Sanford and Maria Stamas of the Rocky Mountain Institute describe “passive design,” the techniques for building structures that work for humans within the natural constraints of the environment. Buildings sited for optimal use of daylight, equipped with thermal mass to keep them cool in summer and warm in winter, using passive ventilation systems, and so on, can use significantly less energy than “normal” buildings.

Consider the Anasazi Indians. They constructed high-mass adobe dwellings in southern-facing caves in the American West. In the winter, when the sun follows a lower path, their designs harnessed the sun’s direct heating energy, and during the summer, when the sun follows a higher path, rock overhangs blocked heat gain and the sun’s harsh rays.

Though they didn’t realize it at the time, the Anasazi employed passive design — using the sun’s energy to light, cool, heat and ventilate a building’s interior.

Sanford and Stamas go on to provide a lot more background on passive design and its benefits for building owners, occupants, and the global environment.

As an example of the power of passive design, especially when combined with renewable energy sources, they pointed out this office building under construction in a suburb of Paris which will create more energy than it uses.

Patrick Getreide, who is leading the Energy Plus project with partner Marc Eisenberg, said: “It will be the first building in the world to be ‘energy plus’ and carbon zero.”The proposed building, which will be more than 70,000 sq m and house up to 5,000 people, will produce enough of its own electricity to power all the heating, lighting, and air conditioning required by tenants. It will also generate carbon credits which it hopes to trade for money in the future.

Energy Plus building visualization

Getreide acknowledges that this isn’t the cheapest way to build a building (yet), but anticipate that tenants will end up paying about the normal rate for premium office space in their location. And of course, they won’t have energy bills.

By using integrated design, including solar PV collection, optimal siting, and a cutting-edge form of insulation, the team expects electricity consumption per square metre of office space per year of 16 kilowatts, lower than any other building in the world of this size. Most modern buildings use between 80 and 250 kilowatts per square metre, while older ones often use up to 300 kilowatts.

Because commercial real estate is a conservative industry, this project required investment from non-traditional sources, including former President Clinton’s Global Initiative and support from several governments. Rocky Mountain Institute is a key advisor on the project as well.

The California Clean Tech Open, a three-year-old competition for clean technology startups, got a nice little present from the Department of Energy the other day – a $100,000 grant focused on sustainable building technologies.

The Clean Tech Open focuses on an annual “Business Plan” competition, where clean tech entrepreneurs compete for the six top prizes of a $100,000 “startup in a box” including office space, cash, and services. They’ve already awarded over $1.2 million in prizes, and over three-quarters of their winners are still in business and have raised nearly $70 million in funding.

The DOE grant, part of their Zero Net Energy Commercial Building Initiative (CBI),is intended to help the Clean Tech Open initiate a clean building category in the competition. Despite the relatively small amount of the grant (for now), it’s a significant milestone. This is the first disbursement in a $250 million program that the DOE and other agencies are administering with the goal of “all new commercial buildings to be so efficient in energy consumption and in on-site renewable energy generation that they offset any energy use from the grid,” part of the Energy Independence & Security Act (EISA) of 2007 passed by Congress and signed by President Bush last year.